Problem: Multiply.
Answer: Let's visualize to help us solve. The array shows ${9}$ rows with ${4}$ dots in each row. $1$ $2$ $3$ $4$ $5$ $6$ $7$ $8$ $9$ $1$ $2$ $3$ $4$ ${9} \times {4} = \underbrace{{4} + {4}+ {4} + {4}+ {4} + {4} + {4}+ {4} + {4}}_{{9}{\text{ fours}}} = 36}$ $36}={9}\times{4}$